De novo assembly of the transcriptome of Acanthaster planci testes

Abstract

A key strategy to reduce coral loss is the development of effective control method for the corallivorous crown-of-thorns sea star (Acanthaster planci), an omnipresent scourge and threat to the biodiversity of reefs in the Indo-Pacific region. Limited genetic resources are available for this highly fecund species. In this study, we explored one aspect at the heart of A. planci outbreaks, the male reproductive system. Using high-throughput sequencing technology, we report for first time the production of a comprehensive transcriptomic data set for the testes of A. placni that can aid in understanding the molecular mechanisms involved in A. planci spermatogenesis and fertilization. Through de novo transcriptome sequencing, we produced 52 965 998 raw reads corresponding to 4.76 Gb clean read data. From this, 243 870 contigs were assembled with Trinity and used to construct 92 792 unigenes. Distinct genes were then annotated with blastx yielding 30 810 unigenes above the cut-off E-value set at 10(-5) , with ESTScan database query analyses yielding up to 5366 unigenes to known hits. The identification of genes directly involved in sperm development (DEAD-box family proteins), motility, fertilization and signalling (Bindin/Speract receptor) are also discussed.

Gene expression profiling during the embryo‐to‐larva transition in the giant red sea urchin Mesocentrotus franciscanus

“…From these unigenes, 60,439 (~34%) were blasted to known proteins in the public databases NCBI (nr) and UniProt (Swiss‐Prot and TrEMBL), while 116,446 (~66%) had no matches and may represent: (1) specific unigenes of M. franciscanus with unknown function; (2) sequences with low similarity to those compared in public databases; and/or (3) chimeric sequences. Although the percentage of unigenes with a BLAST‐hit may appear to be relatively low, we found that the number of unigenes with significant alignments (≤1 e −5 ) to known proteins in M. franciscanus is higher than those reported in other studies with nonmodel echinoderms (Delroisse et al., 2015; Dilly et al., 2015; Gaitán‐Espitia, et al, 2016; Gillard, Garama, & Brown, 2014; Pérez‐Portela, Turon, & Riesgo, 2016; Stewart, Stewart, & Rivera‐Posada, 2015; Vaughn, Garnhardt, Garey, Thomas, & Livingston, 2012; Zhou et al., 2014). Most of the annotated unigenes hit against the purple sea urchin Strongylocentrotus purpuratus (88.4%), followed by the acorn worm Saccoglossus kowalevskii (1.5%), and the Pacific oyster Crassostrea gigas (<1%; Fig.…”

Thirty Years of Research on Crown-of-Thorns Starfish (1986–2016): Scientific Advances and Emerging Opportunities

“…The era of genomics on CoTS using HTS technologies has just started to emerge. By sequencing the transcriptome of the male gonad of CoTS, using an RNA-Seq approach, key candidate genes involved in reproduction were identified [263]. This study found that CoTS contain proteins, molecules, signalling pathways and key developmental genes that are known to have a role in sperm motility and signalling in other echinoderms [263].…”

“…By sequencing the transcriptome of the male gonad of CoTS, using an RNA-Seq approach, key candidate genes involved in reproduction were identified [263]. This study found that CoTS contain proteins, molecules, signalling pathways and key developmental genes that are known to have a role in sperm motility and signalling in other echinoderms [263]. A recent study using genome sequencing and proteomics in combination with behavioral experiments, allowed the identification of key species-specific pheromones involved in their aggregation [176].…”

30 Years of Research on Crown-of-thorns Starfish (1986-2016): Scientific Advances and Emerging Opportunities

“…By sequencing the transcriptome of the male gonad of CoTS, using an RNA-Seq approach, key candidate genes involved in reproduction were identified (Stewart et al 2015). This study found that CoTS contains proteins, molecules, signaling pathways and key developmental genes that are known to have a role in sperm motility and signaling in other echinoderms (Stewart et al 2015). In a recent study, using genome sequencing and proteomics in combination with behaviour experiments, allowed the identification of key species-specific pheromones involved in their aggregation .…”

“…The era of genomics on CoTS using HTS technologies has just started to emerge. By sequencing the transcriptome of the male gonad of CoTS, using an RNA-Seq approach, key candidate genes involved in reproduction were identified (Stewart et al 2015). This study found that CoTS contains proteins, molecules, signaling pathways and key developmental genes that are known to have a role in sperm motility and signaling in other echinoderms (Stewart et al 2015).…”